Заготовка для генератора картинки

lab3/src/Lib.hs

@@ -10,6 +10,7 @@ module Lib
 
 import Codec.Picture
 
+import Data.Word (Word8)
 import Data.Char (ord, chr)
 import Data.Bits (testBit)
 import qualified Data.Vector.Unboxed as VU
@@ -41,21 +42,36 @@ decryptCaesar alphabet shift =
 
 textToBits :: String -> VU.Vector Int
 textToBits text = VU.fromList $ concatMap charToBits text
-    where 
-        charToBits c = [if testBit (ord c) i then 1 else 0 | i <- [7,6..0]]
+
+charToBits :: Char -> [Int]
+charToBits c = [if testBit (ord c) i then 1 else 0 | i <- [7,6..0]]
 
 bitsToText :: VU.Vector Int -> String
 bitsToText bits
     | VU.null bits = []
     | otherwise = (chr $ bitsToInt (VU.take 8 bits)) : bitsToText (VU.drop 8 bits)
-    where
-        bitsToInt charBits = 
-            sum [bit * (2 ^ index) | (bit, index) <- zip (VU.toList charBits) [7 :: Int,6..0]]
+
+bitsToInt :: VU.Vector Int -> Int
+bitsToInt charBits = 
+    sum [bit * (2 ^ index) | (bit, index) <- zip (VU.toList charBits) [7 :: Int,6..0]]
 
 encodePixel :: Int -> Image PixelRGB8 -> VU.Vector Int -> Int -> Int -> PixelRGB8
-encodePixel encodeBitsCount img bits x y = PixelRGB8 newR newG newB
+encodePixel bitsPerByte img bits x y = PixelRGB8 newR newG newB
     where
+        width = imageWidth img
+
+        index = x + y * width
+        startPos = index * 3 * bitsPerByte
+        pixelBits = VU.slice startPos (3 * bitsPerByte) bits
+
+        intToWord8 :: Int -> Word8
+        intToWord8 x = fromIntegral x
+
+        bitsR = intToWord8 $ (VU.take bitsPerByte pixelBits) VU.! 0 
+        bitsG = bitsToInt $ VU.take bitsPerByte $ VU.drop bitsPerByte pixelBits
+        bitsB = bitsToInt $ VU.drop (2 * bitsPerByte) pixelBits
+
         PixelRGB8 r g b = pixelAt img x y
-        newR = b
-        newG = g
-        newB = r
+        newR = bitsR
+        newG = intToWord8 bitsG
+        newB = b